Air-pump



(No Model.)

W. WHITACRE. AIR PUMP.

No. 544,473. Patented Aug. 13, 1895.

EL l l IIIIII c UNITED STATES WILLIAM c. wHI'rAoRE,

OF ST. LOUIS, MISSOURI.

AIR-PUMP.

SPECIFICATION forming part Of Letters Patent NCA). 544,473, dated.August 13, 1895. Application ledAOctober 18, 1894:. Serial No. 526,240.(No model.)

ToaZZ whom it may concern- Beitknown that I, WILLIAM C. WHITACRE, acitizen of the United States, residing at the cityof St. Louis, State ofMissouri, have invented a new and useful Improvement in Air- Pumps, ofwhich the following is a full, clear, and exact description, referencebeing had to Vthe accompanying drawings, forming part of thisspecification, wherein- Figure is a top planview of my improved pump.Fig. 2 is a vertical longitudinal sectional view, and Fig. 3 isa sideelevational View.

This invention relates to a new and useful improvement in air-pumps ofthat'class which are especially adapted for use of street-cars tofurnish power, in the form of compressed air, to operate the brakemechanism.

The objects of this invention are to provide a pump of the classdescribed which :may be'operated from the car-axle, one whose operationwill not be materially affected by the vibration of the axle upon whichit is mounted, and one which is simple, compact, easily applied, andwhich will occupy but small space.

With these objects in view the invention consists essentially in thepeculiar manner of mounting the pump on the axle, whereby the vibrationof the axle will be absorbed before it is communicated to the piston androd, as will hereinafter be described, and afterward pointed outin theclaims.

In the drawings, A indicates the car-axle, upon which is clamped orotherwise secured an eccentric B.

C is the eccentric strap, preferably made in two pieces, for obviousreasons, which strap has means provided for the pivotal attachment of abeam or cross-head D. Pivotally connected to the ends of this cross-headD are two links E, which extend forward and are pivoted at their forwardor opposite ends upon the piston-rod cross head F, which cross-head F issecured to the outer end of piston-rod G.

From the above connections between thel axle and piston-rod G it will beseen that any side play or lateral movement between the axle andcylinder will be taken up by the pivotal connection between thecross-head D and links E, while vertical motion of either of the partswill be compensated for by the pivotal connection between the links Eand the piston-rod crosshead F.

' H indicates the pump-cylinder,in which is a plunger or piston I on theend of piston-rod G. Suitable packing is provided for this rod,

and in order to preserve intactness I arrange on the end of the'cylindera pivoted anglelever h, which engages in notches on the packing-nut hand holds the same in position, said angle-lever being held to its workby the impelling force of a spring h, seated beneath its dependingmember.

-' The valve mechanism of the pump is located in juxtaposition to thecylinder H, and may be said to consist, preferably, of four valvesJ,'J2, J3, and J4.

.Leading to the chambers beneath the valves J and J2 are inlet-ports,the mouths of which are preferably covered by wire-gauze'y to prevent asmuch as possiblethe passage of foreign particles in the form of dirt,cinders, dust.,

dac., into the pump. These valves J and J2` are inwardlyopening valves,and located thereabove or beyond said valves are ports j', leading toeach end of the cylinder H. Ports 7" act as inlet and exit passages toeach end of cylinder H, and when used as exit-passages, as illustratedto the left of Fig. 2, lead beneath the Valves J3 and J4, which arelocated relative to the ports j opposite the valves J and J 2.

The operation of the valves of the pump will be clearly understood byreference to Fig. 2, Where, assuming the piston is just commencing itsout-stroke to the left, it will seat valve J4 and suck in air throughthe righthand port j', valve J2 rising to permit this. vThe air in theouter or left-hand end of the cylinder will seat valve J', and raisingvalve J 3 will force the air into the chamber located beyond the valvesJ 3 and J4, whence the air will be conducted by pipe K into` a Asuitablereservoir, ready to be drawn upon as needed. The inner end of thecylinder H isclosed by a head, upon which are formed bracket extensionsstraddling the eccentricand its connections and forming substantially ahousing therefor. These bracket extensions are mounted uponthe'car-axle, and in this manner the cylinder may be said to bepivotally mounted on the axle, in order that lost play IOC) in theconnections between the eccentric and piston-rod may be avoided. Iprefer in some instances, however, to yieldingly support these bracketson the axle, and to accomplish this arrange on the axle two split boxesL, which are slidingly mounted in vertical ways formed in the bracketextensions, between which boxes and bracket extensions are arrangedsprings M and N, the former being acompression-spring to sustain theweight of the inner end ofthe cylinder and its associate parts and thelatter being a bufferspring to prevent the boxes or springs M beingdisplaced and at the same time absorbing any shock or jar which mightotherwise be communicated to the bracket extensions, due to the suddendrop or fall of the axle. The cylinder is supported at its opposite orfree end in any suitable manner, but is preferably yieldingly suspendedfrom a cross-bar on the truck-frame, which is not shown in the drawings.Suitable connection between the outer end of the cylinder and itssupport can be made through the medium of lug Il', which is preferablyarranged transversely to permit lateral movement of the cylinder withoutcramping.

It will be noted from the above that when the car is moving theeccentric will be revolved with the axle and eommunicatea reciprocatingmovement to the crosshead D, which in turn transmits such motion to thepiston and its rod through the links E and the piston-rod cross-head F.On the reciproeation of the piston the air will be pumped through pipe Kinto a suitable receiver or reservoir, which is provided with anescape-valve to keep the pressure within certain limits. Any shock orjar due to the axle-wheels ruiming over irregularities in the track willnot be communicated to the cylinder, because of the interposition of thesprings M and N and the pivotal connections between the eccentric and`piston-rod. Lateral movement of the axle is permitted to a slightdegree, but such movemeut has no direct effect on the cylinder orpiston-rod connections by reason of the pivotal connections between thecross-head D and the links E. Virtually there are no direct connectionsbetween the axle and pistonrod, and any movement of the axle which mightbe detrimental to the workings of the pump is counteracted in the mannerheretofore described.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

l. In an air-pump the combination with a car-axle, of an eccentricmounted thereon, a cross-head D which is pivoted to the eccentric linksE which are pivotally connected to the ends of the cross-head, thecross-head F pivoted in the opposite end of links E, a piston rod havinga piston, which rod is mounted in the cross-headF, and a cylinder inwhich the piston operates, said cylinder having bracket-extensions whichare yieldingly and pivotally mounted on the car-axle, substantially asdescribed.

2. In an air pump for railway cars, the combination with the pumpcylinder, of bracket extensions thereon, a truck axle which is embraeedby said extensions, and springs interposed between the extensions andaxle, sul stantially as described.

3. In an air pump for railway cars, the combination with the pumpcylinder, of bracket extensions thereon, which extensions are formedwith ways in their ends, a truck axle, boxes on said axle which move insaidways, and springs M and N interposed between the bracket extensionsand boxes, substantially as described.

In testimony whereof I hereunto aflix my signature, in presence of twowitnesses, this 13th day of October, 1894.

WILLIAM C. IVIII'IACRE.

Witnesses:

F. R. CORNWALL, IIUeI-r K. WAGNER.

